Grafting and Budding Nursery Crop Plants
Grafting and budding are horticultural techniques used to join parts from two or more plants so that they appear to grow as a single plant. In grafting, the upper part (scion) of one plant grows on the root system (rootstock) of another plant. In the budding process, a bud is taken from one plant and grown on another.
Although budding is considered a modern art and science, grafting is not new. The practice of grafting can be traced back 4,000 years to ancient China and Mesopotamia. As early as 2,000 years ago, people recognized the incompatibility problems that may occur when grafting olives and other fruiting trees.
Since grafting and budding are asexual or vegetative methods of propagation, the new plant that grows from the scion or bud will be exactly like the plant it came from. These methods of plant reproduction are usually chosen because cuttings from the desired plant root poorly (or not at all). Also, these methods give the plant a certain characteristic of the rootstock - for example, hardiness, drought tolerance, or disease resistance. Since both methods require extensive knowledge of nursery crop species and their compatibility, grafting and budding are two techniques that are usually practiced only by more experienced nursery operators.
Most woody nursery plants can be grafted or budded, but both processes are labor intensive and require a great deal of skill. For these reasons they can be expensive and come with no guarantee of success. The nurseryman must therefore see in them a marked advantage over more convenient propagation techniques to justify the time and cost.
Clones or varieties within a species can usually be grafted or budded interchangeably. For example, Pink Sachet dogwood can be budded or grafted onto White Flowering dogwood rootstock and vice versa. Bradford pear can be grafted or budded onto Callery pear rootstock and vice versa. However, Pink Sachet dogwood cannot be grafted or budded onto Callery pear.
Grafting and budding can be performed only at very specific times when weather conditions and the physiological stage of plant growth are both optimum. The timing depends on the species and the technique used. For example, conditions are usually satisfactory in June for budding peaches, but August and early September are the best months to bud dogwoods. Conversely, flowering pears can be grafted while they are dormant (in December and January) or budded during July and August.